Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The one ounce (1 oz) gold coins are denominated as One Hundred Pounds (£100).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art. The coins are typically "one-year" types usually issued in parallel with smaller denominations with the same reverse designs.
The coins of the Britannia range in 2005 bear a new reverse design, the fifth image of Britannia by Philip Nathan. On it, Britannia is shown seated, similar to the personification of Britannia originally used on coins of the Roman Emperor Claudius, and then on British halfpennies and farthings since 1672.
According to the official announcement:
"To continue the Britannia series, the Royal Mint again looked to award winning sculptor Philip Nathan. His new Britannia, the fifth since the bullion coins were introduced in 1987, shows Britannia in more traditional pose. Ever watchful, she sits at the seashore, her helmet and robes harking back to her Roman roots and her trident and shield recalling her great maritime history."
The composition of the coin is 91.77% gold alloyed with 8.23% silver. The one-ounce (1oz) gold coin was only issued in mint sets in Proof FDC grade, and not individually. | 
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